The Central-Wan Chai bypass has, after more than a decade of debate, finally been given the go-ahead. Now the plan should progress swiftly. Hopefully, it will live up to the promise that it will deliver less congestion and greater public access to the harbour. But the approval should not be the end of the matter. Instead, it has to be the spur for development of a comprehensive strategy for traffic flow in Hong Kong - with electronic road pricing at its heart.

Construction is scheduled to begin at the end of the year on a tunnel, harbourside promenade and associated projects. But the by-pass plan should go hand in hand with a road-pricing scheme for Central. The main argument officials have used for not implementing road pricing has been that drivers heading for destinations beyond the central business district would be unfairly penalised because they had no alternative but to use its streets. Building the bypass, which will go underground near the Two IFC office tower, eliminates this problem.

Environmental concerns have dogged the project. Legal challenges to planned harbour reclamation delayed the work and prompted revisions to the plans. A vocal harbour and environmental protection movement sprang up because of the government's apparent indifference to our most valuable natural asset. Public opinion backed efforts to protect the harbour.

Environmental concerns are a significant reason why road pricing is necessary. Vehicle emissions are largely responsible for our poor roadside air quality. Drivers will think twice before venturing onto our busiest streets if they must pay to use them. Fewer cars naturally means less pollution. Reducing congestion is the other part of the road-pricing equation. At peak times the streets of Central are clogged, considerably lengthening travel times. Charging for road use will convince a proportion of drivers to use public transport instead. The by-products of cleaner air and better traffic flow cannot be ignored.

Road pricing has been controversial in most cities where it has been put in place. The government is aware that this will also be the case in Hong Kong - hence the 25 years that have passed since the idea was first mooted. If a pilot scheme carried out then had been implemented, Hong Kong would have pioneered electronic road pricing; as it is, our city has suffered the consequences and now has to play catch-up.

The bypass aims to reduce congestion, but it will achieve a minimal reduction in jams. The streets of Tsim Sha Tsui and Mong Kok will remain gridlocked. Traffic to the Cross-Harbour Tunnel at peak hours will still be backed up for kilometres. An all-encompassing review of traffic flow is still required.

Innovation is necessary. There is no reason why the Cross-Harbour Tunnel, the busiest by far, should have the lowest toll. Central is not our only congested district. Electronic road pricing is a big part of the answer. The government can no longer delay working towards its introduction.